Field of the Invention
The present invention relates to an infusion and blood collection device and method. In particular, the present invention is directed to an infusion and blood collection device that allows clean blood collections via an angiocatheter previously installed to administer intravenous fluids. The present invention is also directed to a method of using the infusion and blood collection device to draw blood from a patient via a previously installed angiocatheter.
Description of Related Art
U.S. Pat. No. 3,610,226 to Albisser discloses a double lumen cannula instrument for the withdrawal of blood over a prolonged period of time. The instrument includes an inner lumen for withdrawing blood and an outer lumen for introducing an anticoagulant diluent. The relative locations of the openings for the inner and outer lumen permit the mixing of the diluent with the withdrawn blood.
U.S. Pat. No. 5,374,245 to Mahurkar discloses an extruded reinforced multiple-lumen catheter for use in medical applications where fluids must flow simultaneously to and from a patient. Blood is withdrawn for a medical procedure (e.g. dialysis) from the patient through one passageway and returned to the patient through another passageway spaced from the first passageway.
U.S. Pat. No. 5,607,401 to Humphrey discloses augmented polymeric hypodermic needles and lancets. The polymeric needles and lancets are stiffened by augmenting means, which includes a slidable guard or foam insert so that they are able to pierce the skin. Without the augmenting means, it is not possible for the polymeric hypodermic lancet to pierce the skin.
U.S. Pat. No. 5,637,399 to Yoshikawa et al. discloses an extruded synthetic resin needle that is reinforced with combustible fibers. The needle provides a single path administering or withdrawing fluids from a patient.
The prior art described above does not provide for a catheter assembly that is capable of prolonged insertion in the patient for both the simultaneous administering of intravenous fluids and the periodic withdrawal of blood without mixing the intravenous fluid with the withdrawn blood.
U.S. Pat. No. 6,758,835 to Close et al. discloses a micro-injection molded disposable needle assembly having more than one passageway formed therein to permit the simultaneous drawing and administering of fluids through separate passageways. The micro-injection molded disposable assembly includes one or more sensors disposed therein for measuring and monitoring one or more desired body or surrounding environmental conditions. It also discloses a method of forming the disposable needle from an elastomeric material using micro-injection molding.
The invention herein is partly an extension of the device and method disclosed in U.S. Pat. No. 6,758,835 to Close et al. Accordingly, the disclosure of U.S. Pat. No. 6,758,835 is incorporated herein by reference in its entirety.
The devices described in the above prior art focus primarily on the catheter portions of needle assemblies that are capable of prolonged insertion in patients for both the simultaneous administering of intravenous fluids and the withdrawal of blood without mixing the intravenous fluid with the withdrawn blood.
Unlike the above prior art, the invention herein does not focus primarily on the catheter portion of the needle assembly. Instead, it provides a device that may be inserted between a standard, previously installed intravenous (IV) catheter and a standard IV infusion line, and permits the performing of clean blood collections without interrupting the administering of IV therapy to the patient. For example, IV infusion pumps are typically stopped for 30 seconds or more for any blood collection obtained from the peripheral catheter and the connection between the IV catheter and infusate line are disconnected in order to pull the blood sample through the IV catheter and avoid infusate mixing with the blood collection that can cause erroneous results. If the IV infusion pump is not stopped and a downstream valve (e.g., a 2-, 3-, or 4-way stop cock valve) is used to stop the infusate administration, then a pump alarm this sets off, requiring staff attention because the line is considered occluded. Such fluid infusion restriction alarms on IV infusion pumps are typically triggered when the fluid being infused increases to over 10 psi. Providing a device that avoids interruption of the IV therapy prevents stopping the IV infusion pump or triggering an infusion restriction alarm. Further, the device herein has the purpose of reducing the complexity of the flow transfer portion of commonly used infusates and blood collection devices. Thus, whereas in some of the above prior art the pressure is sensed and controlled actively to ensure a clean blood collection, in the instant invention, the pressure can be controlled passively, or alternatively or additionally, actively.
When a patient is admitted into a hospital, an emergency room, or some other medical facility, in the vast majority of cases the patient receives an IV catheter of one kind or another. In some instances, the IV catheter is put in place right away upon admission to administer a needed therapy to the patient. In other instances, the IV catheter is put in place simply for risk management reasons, so as to have the catheter ready in case the medical care providers need to quickly administer medications or fluids to the patient. The cannula portion of the IV catheter is placed into a blood vessel, typically in the forearm, hand, or another location in the patient's body, and the connection portion of the IV Catheter to allow IV infusion is typically secured to the outside of the patient's body with any of a variety of available tapes, bands, straps, or other means.
The typical hospital stay for a patient, on average, is around three days, during which it is reported that two or more sets of laboratory tests per day may be carried out on average. This means that at least twice a day a medical technician would have to subject the patient to a blood collection, which is then sent to the laboratory for testing and/or analysis. Usually if the patient already has a catheter strapped in place in one arm via which medications or fluids are being administered, the medical technician would have to use the patient's other arm or another part of the patient's body to perform blood collections. This means that, during a patient's 3-day average hospital stay, there are at least six occasions for the patient to be repeatedly stuck with a needle, which translates into at least six occasions for potential infections to start, hematomas, missed sticks, and skin irritation from tapes and other means. Furthermore, especially in situations involving pediatric patients, hemophiliac patients, HIV patients, patients with dementia and/or similar conditions, and/or other agitated patients who may suffer from fear of needle pricks, or having other elevated risks relating to additional needle insertions, the patient may be subjected to trauma on at least six occasions during their hospital stay, making the blood collection process difficult or otherwise risky.
Moreover, in some situations, the medical technician may use a catheter already installed into the patient's body to draw blood for testing. In those situations, the technician typically has to temporarily discontinue administration of medications or fluids, and perform a lengthy, drawn-out series of flushing steps to guard against incidental contamination of the blood sample with residual IV solutions, medications or fluids, and ensure that the blood sample is clean. Without such flushing steps, a blood sample may, for example, be diluted with a residual IV solution, leading to erroneous test results. Likewise, for example, contamination of the blood sample with a residual IV solution that contains sodium and/or potassium compounds, would result in false test data showing higher concentrations of these compounds.